Gas-engine.



J. W. BRODE'RICK.

GAS ENGINE.

APPLICATION IEILED MAR.11,1909.

Patented June 16, 1914-.

5 SHEETSSHEET l.

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ATTORNEY.

WITNESSES J. W. BRODERICK.

GAS'ENGINB.

APPLICATION IILBD MAR.11, 1909.

Patented June 16, 1914.

J. W. BRODERIOK.

GAS ENGINE.

APPLICATION FILED MAR. 11, 1909.

1,100,212, Patented June 16,1914.

5 SHEETSSHEET 3.

WITNESSES I/VVE/VTOR ATTOR'NEY.

J. W. BRODERIOK.

GAS ENGINE. APPLICATION FILED MAR. 11, 1909. 1,10,212. 1 Patented June 16, 1914.

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ATTORNEY.

NiTED STATES- PATENT OFFICE.

JOHN W. BRODERICK, 0F NEWARK, NEW JERSEY.

GAS-ENGINE.

Specification of Letters Patent. Patented June 16, 1914.

Application filed March 11, 1909. Serial No. 482,651.

To all whom it may concern:

Be it known thatI, JOHN W. BRouERIoK, a citizen of the United States, residing at Newark, in the county of Essex and State of New Jersey, have invented certain Improvements in Gas-Engines, of whlch the following is a specification.

tially compressed charge to drive out the 1 gases remaining in the explosive chamber; to thus secure a charge in a clean chamber, unmixed with any products of the prevlous explosion; to charge the explosion chamber with a larger quantity of gas than can be obtained by suctionof the plston alone; to thus obtain a maximum efficiency; to provide an improved construction for these purposes which shall be both simple and efi'ective, and to obtain other advantages and results as may be brought out in the followin description.

Tteferring to the accompanying drawings, in which like numerals of reference indicate corresponding parts in each of the several figures, Figure 1 is a rear elevation of an engine of my improved construction, showing the cylinder connecting ducts; Fig. 2 is a plan of the engine, partly in section on line 2 2 of Fig. 1; Fig. 3 is a front elevation of the engine, showing the fuel supply means and exhaust, one of the cylinders being in central vertical sectlon; Fig. 4 is an end view of the engine with the near cylinder partly in central vertical section; Fig. 5 is a section similar to Fig. 4, showing the piston at the end of its outward stroke, and Fig. 6 is a detail section of a certain cylinder ring.

In said drawings, 10 indicates the main shaft, having cranks 11, 111 inclosed in a crank case 12, and 13, 113 are cylinders mounted on said crank case in position for the connecting rods 14, 114 of their pistons to extend a the said cranks 11, 111, respectively.

Supports, as 15, on the interior of the crank casing, with lower straps, as 16, are adapted to hold the outer member or cone 17 of ball bearings for the main shaft 10, I the inner member or cone 18 being screwed upon the shaft and fixed by a lock nut 19.

Bearings, as 20, in the ends of the crank .caseffor said shaft 10, have each an oil groove 21 with drain duct 22 leading back into the crank case, and an annular recess for a felt ring 23 to stop the outward escape of oil. Also, within the crank case, a spiral gear 24 is shown keyed upon the shaft 10, held by a nut 25, and meshing with another spiral gear 26, on a time shaft 27 which extends transversely of the main shaft and has its bearings in the sides of the crank case.

The cylinders 13 and 113 are alike, and hence a description of one will suffice for both, the reference numerals of the parts of the one described being applied to the same parts of the other with a figure 1 prefixed. The cylinder 13, therefore, has near ifls lower end an exterior flange 28 which seats upon the crank case, the lower end of the cylinder depending into the crank case. Interiorly, the lower portion of the cylinder forms a large chamber 29 and its upper portion forms a small chamber 30. The piston is correspondingly stepped, having a small end portion 31 fitting the small chamber 30 of the cylinder and a large portion 32 fitting the large chamber 29. The connecting rod 14 extends into the hollow interior of the piston and is pivoted thereto near its inner end upon the wrist pin 33. The relative lengths of the two piston sections 31 and 32 are such that when the entire piston is at the inner end of its. stroke, the end of the small portion 31 approaches nearly to the end of the cylinder and the end of the large'portion 32 of the piston provides a space between itself and the inner end of the lar e chamber 29 of the cylinder.

1% will be noted by an inspection 3 and 5 of the drawlngs that the large portion 32 of the piston makes the greater portion of its stroke beneath the point of support of the cylinder, and that upon the upstroke said large portion 32 extends scarcely above the supporting flange 28. This is of special importance in an engine of the type ing to the cylinder 13 from a main pipe 38,

which can be connected in any suitable man- .ner to a carbureter, furnishes gas to the said cylinder. The said pipe 37 commumcates through a chamber 39 with the upper part of the large chamber 29 of the cylinder, and in said connecting chamber 39 is an inwardly opening valve 40 normally held closed by a spring 41. It will be understood that the large portion 32 of the piston draws fuel gas into the large chamber 29 of the cylinder upon outward movement of the iston.

At the back of the engine, or at the side opposite the said fuel supply means just described, the cylinder has near the upper part of its large chamber 29, an outlet consisting of a series of ports 42 and from these ports 42 a duct 43 leads to an inlet to the small chamber 130 of the other cylinder, said inlet comprising a series of ports such as shown at 59 on the cylinder 13. Obviously as the piston in the cylinder 13 moves inward on its stroke, its large portion 32 y will partially compress the fuel gas trapped in the large chamber 29 and force it out through the duct 43 to the small chamber 130 of the other cylinder. A flap valve 44 guards the outlet ports 42, and prevents any possibility of back-firing into the compression chamber 29.

As already stated, the large portion of each piston provides between itself and the inneraend of the large chamber in which it reciprocates a space which is never traversed by said large portion of the piston. It is in this space, preferably in the said walls thereof, as shown, that the fuel inlet and outlet ports of the compression chamber are lo-,

Gated, said ports being thus between the inner end of the compression chamber "and the inner limit of travel of the inner end of the large piston portion in said chamber. This construction avoids having the large portion travel across the fuel inlet and outlet ports, and answers everypurpose since the compression chamber does not need to be cleaned out, at each stroke and'the pressure generated in it permits the use of valves in said ports.

It will be noted that the cranks 11 and 111 of the two cylinders are oppositely arranged,

so that when one piston has reached its innermost position in the cylinder, the other is at its outermost position. In such outermost position the piston of the cylinder 13 has uncovered the inlet ports 59, and has also uncovered exhaust ports 45 at the opposite side of the cylinder and which exhaust ports open into an exhaust tube 46 arranged horizontally above the gas supply-pipes 37 and being common to both cylinders. new partially compressed charge thus enters the small chamber 30 of the cylinder while the gases of the previous explosion are being exhausted, and the said new charge in fact serves to completely expel the said gases. The new charge, in a perfectly clean chamber is thus provided ready for the next explosion. In order to prevent the new charge from passing directly across the cylinder to the exhaust, a deflector 47 is arranged upon the end of the piston. The new charge thus introduced into the explosion chamber of the cylinder in a partly compressed condition is further compressed by the immediately succeeding inward stroke of the piston, the large portion 32 of said piston at the same time compressing in the compression chamber of the same cylinder a charge ready for the explosion chamber of the other cylinder. The seat for a spark plug (not shown) is shown at 48 in Figs. 4 and 5 and at 148' in Fig. 2.

The small portion 31 of the piston is provided with piston rings 49 at its inner end, and the large portion 32 of the pistonalso has packing rings 50. The interior wall of the compression chamber 30 of the cylinder is also provided with a packing ring 51 for the small portion 31 of the piston, sald packing ring 51 being located adjacent to the compression chamber 29. This packing ring 51, which is shown in detail cross section in Fig. 6, has beveled corners or edges 52 at its projecting face 53, whereby when the piston is withdrawn from the cylinder for purposes of repair or the like, its piston rings 49 at the 'inner end will pass the said packing ring 51. It will be understood that this packing ring 51 serves the important purpose of absolutely preventing any leakage from the large outer chamber of the cylinder into the small inner chamber, around the piston therein and so to the inlet or exhaust ports, when the piston is at the inner portion of its stroke so that its packing rings are beyond said inlet and exhaust ports. At this time compression has taken place in the outer large chamber and without a packing ring 51 it would be impossible to avoid leakage from the large cylinder through to the inlet and exhaust ducts of the small-cylinder. An ordinary packing ring can not be used in this place, however, because the packing rings of the small piston will not pass such ordinary-packing rings in the cylinder walls when occasion demands V that the piston be entirely withdrawn from the cylinder. By my improved construction of packing ring set forth all of these difiiculties are obviated.

By my improved construction, it will be noted, the compression chamber of one cylinder receives fuel as through the valve 40 at one side of itsel and forces said gas out, on its way to the explosion chamber of the other cylinder, at its opposite side. This insures that at the very beginning of operation theair in the compression chamber will be swept out by the fuel gas, so that pure gas alone will be supplied to the combustion chamber of the other cylinder after the first stroke or two of the piston. The gas entering the explosion chamber is also exhausted at the opposite side thereof after explosion as has been noted, and thus finally issues at the same side of the engine as that at which it entered. This is clearly seen from the drawings, the gas supply pipe 38 to the lower compressing chambers and the exhaust pipe 46 from the upper explosion chambers, being on the same side of the cylinders. The gas in its passage through the engine thus makes a complete circuit from one side to the other and then back again.

The crank case 12 is divided on a horizontal plane through the main shaft 10, and a lower portion 54 provided which is detachably held by screws 55. Furthermore, the lower edges of the upper or main portion of the crank case are extended as at 56 to provide a base for securing the engine in position, said base being strengthened by bracing ribs 57 and having extensions 58, 58 to receive one the magneto generator and the other the water pump (not shown). These extensions 58, 58 are adjacent to the projecting ends of the time shaft 27, and thus the said pump and magneto are very simply and conveniently connected up to the said shaft.

It should be noted that each of the cylinder ports in my improved engine consists of a series or row of small holes preferably drilled through the wall of the cylinder. The advantages of this construction are that a. piston can pass such a port without any In a gas engine, the combination of a crank shaft, two pistons each having a spherical top and each having a large portion next said crank shaft and a small portion in axial alinement with said large portion between said large portion and spherical top, pitmen connecting said pistons to said crank shaft, cylinders fixed with respect to said pistons and each having an inner.

small explosion chamber the end wall of which is spherical upon a smaller radius than said piston top and each having an outer large compression chamber fitting said small and large portions respectively of one of the pistons, the small explosion chamber.

having charge and exhaust ports located between the opposite limits of travel of the inner end ofthe piston in said chamber, said spherical piston top imparting an initial upward movement of the gases entering through the charge port, a deflector to complete the upward deflection of the ingoing charge, said charge following around the spherical inner wall of the cylinder and expelling the burntgases from the cylinder, said large compression chamber having fuel inlet and outlet ports both located between its inner end and the inner limit of travel of the inner end of the piston portion in said chamber, means for supplying fuel to the inlet port of the compression chamber, an inwardly-opening check valve in said inlet port, and ducts for connecting the outlet port of the compression chamber of each cylinder to the charge port of the'explosion chamber of the other cylinder.

JOHN W. BRODERICK.

In the presence of' RUSSELL M. EVERETT, FRANcns E. BLODGETT. 

